A. Technical Field
The present invention relates to a signal processor, and more particularly, to systems and methods for processing readout signals from multiple axes of a gyroscope.
B. Background of the Invention
A rate of rotation sensor has been widely applied to measure the angular velocity of a moving object. FIG. 1 shows a schematic diagram 100 of a conventional gyroscope for measuring the rates of rotation of a sensor along three axes. As depicted, gyroscope 100 includes: a sensor unit 102 having multiple sensors 104a, 104b, and 104c disposed along x, y, and z axes, respectively; and a signal processor 108 for processing sensor signals 106a, 106b, and 106c from multiple sensors 104a, 104b, and 104c, respectively. Signal processor 108 includes three front-end (FE) amplifiers 110a, 110b, and 110c; and demodulators 112a, 112b, and 112c, and filters 114a, 114b, and 114c, where each of the FE amplifiers, demodulators, and filters processes one of the multiple sensor signals 106a, 106b, and 106c. The output from each of filters 114a, 114b, and 114c is further processed to read the angular velocity of sensor unit 102 along an axis.
Since signal processor 108 has three FE amplifiers 110a, 110b, and 110c, it has a large form factor and a high power consumption rate as well as high manufacturing cost. Also, signal processor 108 is implemented mostly in analog domain, i.e., it uses more analog components than digital components. For instance, as depicted in FIG. 1, demodulators 112a-112c and filters 114a-114c operate in an analog domain 118, i.e., these components process analog signals. Also, in addition to the typical factory calibrations, other calibrations, such as an offset compensation for temperature variation, are also performed in the analog domain. Since a large portion of the processes in the conventional signal processor 108 are based on analog functions, signal processor 108 has low immunity to process spread while it has increased form factor, power consumption rate and circuit complexity inherent to the analog components.
Therefore, a better solution is needed to address the main issues, including large form factor, low efficiency in power consumption, and circuit complexity of the signal processor of the conventional gyroscopes.